| Paper | Title | Page |
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| MOPHO04 | Ultra-Low Emittance Light Source with a Torus-knot Type Accumulator Ring | 240 |
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| We proposed a torus knot type synchrotron radiation ring in that the beam orbit does not close in one turn but closes after multiple turns around the ring. This ring is capable to have many straight sections and it is advantageous to installation of many insertion devices. Currently, we are designing a new ring based on the shape of a (11, 3) torus knot for our future plan ‘HiSOR-II.’ This ring is mid-low energy light source ring with a beam energy of 700 MeV. It has eleven 3.6-m-long straight sections though the ring diameter is as compact as 15 m. In late years, some compact light source rings achieved very low emittance of several tens of nmrad. However for the ring we propose, the emittance can be reached less than 10 nmrad when the multi-bend scheme is adopted to the arc section. With this ultra-low emittance, the size and divergence of electron beam is smaller than the diffraction limited light in lower energy part of VUV region, and it will be very useful for many synchrotron radiation users' experiments. We present the details of the lattice and the specifications of this ultra-low emittance light source ring having innovatively odd shape. | ||
| WEPSM01 | Design Study of Knot-APPLE Undulator for PES-Beamline at SSRF | 1043 |
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An intense on-axis radiation power from a linear undulator is a serious problem especially for a low-photon-energy beamline at high or medium energy storage ring. This problem may be solved by using a Figure-8, a Pera, or a Knot undulator configuration [*,**]. However, these schemes are useless for elliptical undulators since such devices are not capable for changing polarizations. Also, among these, only Figure-8 undulators are realized and used in several SR facilities. Pera undulator exists only in a magnet design, and Knot undulator has only a suggested ideal magnetic field variation. In this situation, we have completed a conceptual magnet design of Knot-APPLE udulator which is capable to generate elliptically polarized radiation as well as linearly polarized radiation. This pure permanent magnet device is equipped with a motion mechanism of APPLE undulator. In this paper, we present detailed magnet design feature, magnetic field distributions, and radiation properties including variations of polarization in comparisons with other exotic devices such as Figure-8, Pera, Leaf, and APPLE-8 undulators.
* S. Sasaki, "Undulators, wigglers and their applications," pp.237-243 (Ed. by H. Onuki & P. Elleaume, Taylor & Francis Inc, New York, 2003) ** S. Qiao, et. al, Rev. Sci. Instrum., 80, 085108 (2009) |
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